Horizontal packaging machines use at least one packaging film for packaging the products. To supply this film, said machines comprise a feeding unit, where said film is wound in the form of a reel on a reel holder. The film is unwound and supplied by the necessary means for packaging the products by means of a film driving system or by means of turning the reel holder.
In some horizontal packaging machines, to improve production the feeding unit comprises two reel holders for being able to store a spare reel while the film on the operative reel is supplied for packaging the products. With these feeding units, machines further comprise a splicing unit in which when a first operative reel is almost spent, the film on the second spare reel is spliced to the film on this first reel, and the packaging machine can thereby continue packaging with the film on the second reel when the first reel is spent, without having to stop production to replace an empty reel with a reel that has film.
Machines comprising a splicing unit automatically performing the process of splicing the two films to one another are known, such as the one disclosed in WO2010128441A1, for example. The splicing unit is arranged on one of the sides of the roller shafts, and to splice both films together first one film is arranged on the other, and then they are welded together. Therefore, it is necessary to incorporate devices or elements that entail excessively increasing the final cost and size of the machine, as well as a more complex and expensive maintenance, which cannot always be taken on.
Other more cost-effective methods involve a user's action for splicing the two films to one another, where the splicing (attachment) of the two films is done by means of an adhesive element comprising two opposing adhesive surfaces commonly referred to as two-sided tape. An adhesive surface is adhered to one of the films and the other adhesive surface is adhered to the other film, both films thereby being spliced to one another by means of said adhesive element. First, the adhesive element is adhered to one of the films manually, and then the other film is spliced automatically. For adhering the adhesive element to the first film, the user responsible for doing it must face a series of difficulties which, if not correctly resolved, lead to an incorrect adhesion or accidental tearing of the film, for example, which would entail shutting down the machine. Accessibility to the film stands out among these difficulties: the adhesive element is adhered to the film transversely, covering most of the width of the film. Due to the configuration of horizontal packaging machines, the user has to access the entire width (bottom) of the machine (to cover the entire width of the film) from one side of the machine, which makes the attachment operation uncomfortable and difficult, which could furthermore result, should the operation fail, in the need to remove the poorly packaged product, waste the used film and feed film back into the machine again all of which, in summary, reduces the output of the packaging process and increases the cost.